tree a73c0ae06491d7d1f911fe0dd247e2294c230ce9
parent ed30a4a51bb196781c8058073ea720133a65596f
author Greg Ungerer <gerg@linux-m68k.org> 1699847990 +1000
committer Greg Ungerer <gerg@linux-m68k.org> 1713738270 +1000

m68k: use kernel's generic muldi3 libgcc function

Use the kernels own generic lib/muldi3.c implementation of muldi3 for
68K machines. Some 68K CPUs support 64bit multiplies so move the arch
specific umul_ppmm() macro into a header file that is included by
lib/muldi3.c. That way it can take advantage of the single instruction
when available.

There does not appear to be any existing mechanism for the generic
lib/muldi3.c code to pick up an external arch definition of umul_ppmm().
Create an arch specific libgcc.h that can optionally be included by
the system include/linux/libgcc.h to allow for this.

Somewhat oddly there is also a similar definition of umul_ppmm() in
the non-architecture code in lib/crypto/mpi/longlong.h for a wide range
or machines. Its presence ends up complicating the include setup and
means not being able to use something like compiler.h instead. Actually
there is a few other defines of umul_ppmm() macros spread around in
various architectures, but not directly usable for the m68k case.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>